Waterproof safety footwear

ABSTRACT

A waterproof safety article of footwear and preferably, but not exclusively, constructed with an outer shell formed from EVA (ethyl vinyl acetate) material, is described. It is comprised of an outer boot shell formed of waterproof material capable of being injection molded and an inner protective boot liner which is positioned inside the boot shell. The protective liner has a puncture proof insert, preferably a toe cap and sole plate secured thereto. The outer shell can also be molded from TPR (thermoplastic rubber) material. In order to achieve a maximum light weight safety article of footwear, the protective liner has a toe cap and a sole plate formed from composite materials and the outer shell is molded from EVA material. The method of constructing the waterproof safety article of footwear is also described.

TECHNICAL FIELD

The present invention relates to a waterproof safety footwear and a method of fabrication of same and wherein an inner protective boot liner is removably retained inside an outer waterproof boot shell and wherein the liner has a puncture proof toe cap and sole plate secured thereto. Preferably, but not exclusively, the outer shell is formed from EVA (ethylene vinyl acetate) material.

BACKGROUND ART

Safety footwear has been known for a very long time and such is usually used by construction workers in the form of leather boots in which is integrated a steel toe cap and sometimes, in combination, a steel sole plate. It is also known to fabricate safety protective boots made of rubber material such as thermoplastic rubber (TPR) and wherein a steel toe plate and a steel toe cap is encapsulated in the mold and molded in the rubber. A sock liner is first placed on an aluminum last before inserting the steel toe cap and steel plate. The metal pieces are retained in position on the aluminum last by magnets secured in the last. The mold is then closed and the thermoplastic material is injected. There are several problems associated with such fabrication.

Some of the problems with TPR molded boots is that they are expensive to fabricate due to the high percentage of rejects and labour costs. The molds are also expensive to produce. In an attempt to reduce cost boot rejects are usually cut open whereby to salvage the steel caps which is an expensive item in the manufacture of safety rubber boots. Because the steel plate is retained captive along the entire sole portion of the boot, it would be too labour intensive to try and salvage the plate and it is therefore discarded. Accordingly, there is extensive material loss involved with rejects as well as a loss in labour costs. The production cycle in the fabrication of such boots is also slow due to the fact that the sole plate and toe cap need to be assembled on the mold and encapsulated between liners. A further disadvantage of such rubber safety boots is that they are heavy due to the weight of the thermoplastic rubber as well as the weight of the steel toe cap and sole plate.

It is known to reduce the weight of waterproof articles of footwear by utilizing EVA (ethylene vinyl acetate) material which is waterproof and very light weight as compared with thermoplastic rubber. However, it is not possible to inject this material over a mold on which a steel sole plate and toe cap can be secured as the molding process of such articles of footwear utilizes molds which are of miniature dimension and the boot shell is formed by expansion of the injected material once the shell is removed from the mold. With this process, when the molded EVA shell is removed from the mold it starts expanding and it is immediately placed on a plastic last which is dimensioned to a desired size and the EVA shell is cured on the plastic last whereby to achieve a desired shape and size.

It would therefore be desirable to construct a waterproof safety footwear which is light weight and which could be made at lower production cost with a substantial reduction in the percentage of rejects associated with its manufacture.

SUMMARY OF INVENTION

It is a feature of the present invention to provide a waterproof safety article of footwear which provides the above desired need and wherein the article of footwear can be made of light weight EVA material or TPR material with a substantial reduction in rejects and material and labour costs associated therewith.

Another feature of the present invention is to provide a light weight waterproof safety article of footwear constructed of an outer boot shell formed of EVA material and an inner protective boot liner removably retained therein and provided with a puncture proof protective insert which may be constructed of steel or light weight composite material.

Another feature of the present invention is to provide a waterproof safety article of footwear wherein the outer boot shell is formed from TPR material and further wherein an inner protective boot liner is removably retained inside the outer boot shell and provided with a puncture proof protective insert which may be constructed from steel or light weight composite materials.

Another feature of the present invention is to provide a method of constructing a waterproof safety article of footwear formed from an outer shell and an independent inner protective boot liner which is provided with a puncture proof protective insert to protect a portion of a wearer's foot and wherein the outer boot shell may be formed of light weight EVA material or TPR material.

According to the above features, from a broad aspect, the present invention provides a waterproof safety article of footwear comprising an outer boot shell formed of waterproof material capable of being injection molded. An inner protective boot liner is positioned inside the boot shell. The protective liner has a puncture proof protective insert to protect a portion of a wearer's foot. The puncture proof insert is independently secured to the protective liner.

According to a further broad aspect of the present invention there is provided a method of constructing a waterproof safety article of footwear which comprises the steps of injection molding an outer boot shell with a waterproof injectable material. An inner protective boot liner is formed from fabric material. A puncture proof protective insert is secured to the boot liner to protect a portion of the wearer's foot. The liner with its puncture proof protective insert is then inserted inside the boot.

The method also comprises forming the inner protective boot liner from thermally insulating fabric material and securing both a protective toe cap and a sole plate to the liner and wherein the sole plate and toe cap may be fabricated from either steel material or lighter weight composite materials.

BRIEF DESCRIPTION OF DRAWINGS

A preferred embodiment of the present invention will now be described with reference to the accompanying drawings in which:

FIG. 1 is a perspective view of an inner protective boot liner fabricated in accordance with the present invention;

FIG. 2 is a bottom view of the boot liner of FIG. 1;

FIG. 3 is a fragmented view of the boot liner showing how the toe cap is secured to the liner;

FIG. 4 is a fragmented view illustrating a toe cap which is glued onto the inner protective boot liner;

FIG. 5 is a bottom view of FIG. 4 showing the steel foot plate imprisoned in the protective boot by liner material and imprisoned by stitching together along the feather edge of the boot shell;

FIG. 6 is a perspective view showing an inner protective boot liner secured to an upper by stitching and wherein the toe cap is formed from composite material;

FIG. 7 is a bottom view of FIG. 6 showing the puncture proof sole plate as being constituted by a composite fabric material which is stitched to the sole portion of the boot liner;

FIG. 8 is a schematic side view illustrating an outer boot shell in which an inner protective boot liner has been positioned or permanently secured; and

FIG. 9 is a side view showing a high cut boot shell in which a protective liner has been removably positioned and wherein the outer boot shell is formed from TPR material.

DESCRIPTION OF PREFERRED EMBODIMENTS

Referring now to the drawings and more particularly to FIGS. 1 to 3, there is shown generally at 10 an inner protective boot liner constructed in accordance with the present invention. The boot liner 10 as herein illustrated is comprised of a boot upper 11 formed from felt material although foam or other textile fabric materials may be used and it has a toe portion 12 and a sole portion 13. The front portion of the boot upper 11 is an open portion 14 to facilitate insertion and removal of the boot liner 10 from an outer boot shell such as the boot shell 50 illustrated in FIG. 9. Accordingly, the protective liner 10 is removably retained inside an outer boot shell.

As herein illustrated with more specific reference to FIG. 2, the boot liner has a puncture proof thin steel plate 15 secured to the sole portion 13 thereof such as by gluing it thereto. As shown in FIG. 3, a steel toe cap 16 is also secured over the toe portion 12 of the boot liner 10 and this is herein accomplished by a toe cap retaining fabric liner 17 which is stitched to the boot liner in a rear portion 18 of the liner 17 or it could also be glued to the liner in the rear portion 18 and then overlapped over the steel toe cap 16 and secured to the liner by an overlap portion 19 which extends under the toe cap and onto the sole plate. The overlap portion 19 is herein shown as glued to an overlap edge portion 20 of the toe cap as better illustrated in FIG. 5 and onto the steel sole plate 15. Accordingly, the toe cap 16 is imprisoned in position onto the boot liner.

With reference to FIGS. 4 and 5, it can also be seen that the steel toe cap 16 may be glued onto the toe portion 12 of the boot liner 10 and that the sole steel plate 15 may be imprisoned between the felt sole portion 13 and an outer fabric liner 21. This is accomplished by the contour stitch 22 all about the sole feather edge portion of the boot liner 10 Alternatively, the steel sole plate 15 may simply be glued and also glued and stitched, as illustrated in FIG. 2, with the toe cap also glued to the liner.

Having produced an inner protective boot liner 10 as above described and illustrated by FIGS. 1 to 5, such may then be easily assembled with a boot shell. The liner 10 is simply positioned inside an EVA or TPR outer boot shell. Such is illustrated in FIGS. 9 or 8, wherein in FIG. 8 the shell is a TPR shell 40 and the inner protective boot liner is of low cut design. Accordingly, there can now be manufactured a light weight protective, waterproof boot.

The outer boot shell 50 as shown in FIG. 9 is one constructed of TPR (thermoplastic rubber) with the inner protective boot liner 10″ positioned therein to provide a waterproof safety rubber boot which in its fabrication does not encounter the problems as above-described with reference to the prior art rubber boots molded with protective inserts.

In order to further reduce the weight of the waterproof safety article of footwear fabricated in accordance with the present invention, the toe cap 16 may be fabricated from a composite fiber material 25 as shown in FIG. 6. Further, the protective sole plate may be fabricated from a puncture proof woven composite material 26, as illustrated in FIG. 7, which is a pliable material capable of being stitched along the feather edge contour 27 of the boot liner 10 such as by stitches 28. Such puncture proof liner is formed from synthetic yarn material which is tightly woven together in several layers and readily available on the market such as of the type fabricated by Lenzy Egisto of Italy.

As shown in FIG. 6, the inner protective boot liner is a boat-like shaped liner suitable for securement in the boat-like shape outer shell 40 illustrated in FIG. 8. The liner 30 is hereinshown secured to a finished boot upper 31 by stitching along the shell top opening 32.

Although the inner protective boot liner 10 as herein illustrated and described shows a protective toe cap and a protective sole plate secured to the liner it is intended that the present invention also cover a liner which is provided solely with a toe cap or solely with a protective sole plate depending on the requirements of the finished article of footwear. The outer boot shell may also be of a different construction than above-described. It is also pointed out that by fabricating the inner protective boot liner independently of the outer boot shell that better tolerances can be achieved in the protection of the sole portion of the safety article of footwear wherein the protective sole plate can be dimensioned to extend very close to the feather edge of the sole portion of the protective liner to about 4 mm from this feather edge 27 as illustrated in FIG. 7. Existing CSA regulation for protective sole coverage is defined by article 3.3 wherein it is stipulated that a protective sole when incorporated into an article of footwear shall cover the maximum area allowed by the construction, including the heel area. The outside edge of the protective sole shall be no more than 7 mm from the feather edge of the last all around the sole from the toe to no less than 13 mm beyond the breast of the heel and shall be within 13 mm of the edge round the heel area. For articles of footwear not incorporating a defined heel, the outside edge of the protective sole shall be no more than 8 mm from the feather edge all around the last. Accordingly, improved protection can now be made available by the method of fabrication of the protective sole as described and illustrated in the accompanying drawings.

Briefly summarizing the method of constructing the waterproof safety article of footwear 40 or 50 of the present invention it consists of injection molding an outer boot shell, such as the shell 40 and 50 in FIGS. 8 and 9 with a waterproof injectable material such as EVA or TPR material. The inner protective boot liner 10 is fabricated from fabric material, preferably, but not exclusively, thermally insulating material such as felt or foam material or suitable textile fabric and securing a puncture proof insert such as a toe cap and/or sole plate. The boot liner 10 with its puncture proof sole plate and toe cap having been secured thereto is then inserted inside the outer boot shell. One can appreciate that when the outer boot shell is fabricated from EVA material the protective waterproof boot is lighter in construction than rubber boots. Further, when the protective toe cap and sole plates are fabricated from composite material this further greatly reduces the weight of the finished article of footwear. It also increases the warmth comfort as the protective pieces are not thermal conduction as are the steel protective inserts. The method also comprises either securing the protective toe cap and sole plate by means of gluing or maintaining them in position by stitching and/or entrapping between fabric materials. It is also pointed out that the protective liner can be glued inside the boot shell when inserted therein to make it immovable within the shell.

It is within the ambit of the present invention to cover any obvious modifications of the examples of the preferred embodiment described herein provided such modifications fall within the scope of the appended claims. 

1. A waterproof safety article of footwear comprising an outer boot shell formed of waterproof material capable of being injection molded, and an inner protective boot liner inside said boot shell, said protective liner having a puncture proof protective insert to protect a portion of a wearer's foot, said puncture proof insert being independently secured to said protective liner.
 2. A waterproof safety article of footwear as claimed in claim 1 wherein said protective liner is removably retained inside said outer boot shell.
 3. A waterproof safety article of footwear as claimed in claim 2 wherein said boot shell is a light weight injection molded shell formed of ethylene vinyl acetate (EVA) material.
 4. A waterproof safety article of footwear as claimed in claim 2 wherein said puncture proof insert is a toe cap immovably secured to a toe portion of said boot liner.
 5. A waterproof safety article of footwear as claimed in claim 4 wherein said puncture proof insert further comprises a sole plate immovably secured to a sole portion of said boot liner.
 6. A waterproof safety article of footwear as claimed in claim 5 wherein at least one of said toe cap and sole plate is formed from one of a composite material or steel.
 7. A waterproof safety article of footwear as claimed in claim 6 wherein both said toe cap or sole plate are formed from one of a composite material or steel.
 8. A waterproof safety article of footwear as claimed in claim 6 wherein said toe cap and sole plate are secured to said protective boot liner by glue.
 9. A waterproof safety article of footwear as claimed in claim 8 wherein said toe cap and sole plate are imprisoned in said protective boot liner between fabric material pieces which are stitched together along predetermined contour lines.
 10. A waterproof safety article of footwear as claimed in claim 2 wherein said boot shell is a thermoplastic rubber (TPR) injected shell.
 11. A waterproof safety article of footwear as claimed in claim 1 wherein said inner protective boot liner has a boot upper secured thereto, said outer boot shell being a boat-like shell, said liner being stitched to said boat-like shell.
 12. A waterproof safety article of footwear as claimed in claim 6 wherein said sole plate extends to about 4 mm from a feather edge of the sole portion of said protective liner.
 13. A waterproof safety article of footwear as claimed in claim 9 wherein said protective boot liner is constructed of felt material, said cap and sole plate being imprisoned between said felt material and an outer fabric retention liner secured to said felt material by stitching.
 14. A method of constructing a waterproof safety article of footwear comprising the steps of: i) injection molding an outer boot shell with a waterproof injectable material; ii) forming an inner protective boot liner from fabric material; iii) securing a puncture proof protective insert to said boot liner to protect a portion of a wearer's foot; and iv) inserting said liner with said puncture proof insert inside said outer boot shell.
 15. A method as claimed in claim 14 wherein said waterproof safety article of footwear is a light weight safety article of footwear, said step (i) comprising injection molding said outer boot shell with ethylene vinyl acetate (EVA) material.
 16. A method as claimed in claim 14 wherein said step (iii) comprises immovably securing a sole plate to a sole portion of said boot liner.
 17. A method as claimed in claim 16 wherein there is further provided immovably securing a toe cap to a toe portion of said boot liner.
 18. A method as claimed in claim 17 wherein said toe cap and sole plate are secured by gluing same to said boot liner.
 19. A method as claimed in claim 18 wherein said toe cap and sole plate are further imprisoned in said protective boot liner between fabric material pieces which are stitched together along predetermined contour lines.
 20. A method as claimed in claim 14 wherein said step (i) comprises injection molding said outer boot shell with thermoplastic rubber (TPR) material. 